Problem: On Saturday, Stephanie's parents gave birth to twins and named them Umaima and Brandon. When they were first born, Umaima weighed 8.59 pounds and was 18.5 inches tall, and Brandon weighed 7.8 pounds. How much did the babies weigh in total?
Answer: To find the weights of the 2 babies, we need to add their weights together. Umaima's weight + Brandon's weight = total weight. ${8}$ ${5}$ ${9}$ ${7}$ ${8}$ ${0}$ ${+\vphantom{0}}$ ${9}$ ${3}$ ${6}$ ${1}$ Together, the babies weigh 16.39 pounds.